首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   9313篇
  免费   382篇
  国内免费   321篇
耳鼻咽喉   56篇
儿科学   119篇
妇产科学   68篇
基础医学   2928篇
口腔科学   71篇
临床医学   1080篇
内科学   1231篇
皮肤病学   20篇
神经病学   914篇
特种医学   522篇
外科学   1201篇
综合类   596篇
预防医学   348篇
眼科学   55篇
药学   555篇
  1篇
中国医学   174篇
肿瘤学   77篇
  2023年   72篇
  2022年   225篇
  2021年   316篇
  2020年   279篇
  2019年   258篇
  2018年   235篇
  2017年   183篇
  2016年   159篇
  2015年   193篇
  2014年   407篇
  2013年   416篇
  2012年   331篇
  2011年   385篇
  2010年   311篇
  2009年   394篇
  2008年   428篇
  2007年   419篇
  2006年   433篇
  2005年   350篇
  2004年   320篇
  2003年   341篇
  2002年   287篇
  2001年   242篇
  2000年   219篇
  1999年   189篇
  1998年   161篇
  1997年   171篇
  1996年   164篇
  1995年   171篇
  1994年   148篇
  1993年   138篇
  1992年   133篇
  1991年   104篇
  1990年   122篇
  1989年   93篇
  1988年   112篇
  1987年   98篇
  1986年   77篇
  1985年   97篇
  1984年   111篇
  1983年   50篇
  1982年   76篇
  1981年   57篇
  1980年   50篇
  1979年   68篇
  1978年   57篇
  1977年   57篇
  1976年   44篇
  1973年   56篇
  1972年   47篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
41.
An application of the rectus abdominis muscle flap to salvage an infected prosthetic graft of the ascending thoracic aorta is presented. The length of this flap along with its width and thickness allows it to be wrapped around prosthetic grafts of the ascending aorta in a spiral fashion. This rectus muscle wrap around flap method is straightforward involving the use of one muscle rather than multiple muscles. The abdominal cavity is not opened as with the use of omentum. The procedure can be accomplished in a short time which is important in the critically ill patient.  相似文献   
42.
The mechanism of the vasodilator effect of pinacidil was examined. Pinacidil (0.1–100 μM) inhibited the increases in cytosolic Ca2+ ([Ca2+]i) and muscle tension due to norepinephrine in rat aorta. In contrast, a Ca2+ channel blocker, verapamil, inhibited the norepinephrine-stimulated [Ca2+]i more strongly than the contraction. Higher concentrations of pinacidil (3–100 μM) inhibited the verapamil-insensitive portion of the contraction and [Ca2+]i. An inhibitor of ATP-sensitive K+ channels, glibenclamide, antagonized the inhibitory effect of low concentrations ( 10 pM) of pinacidol. Pinacidil did not change the contraction induced by Ca2+ in vascular smooth muscle permeabilized with Staphylococcus aureus -toxin. Norepinephrine (in the presence of GTP), 12-deoxyphorbol 13-isobutyrate (in the absence of GTP), and treatment with GTPγS potentiated the contraction of permeabilized smooth muscle induced by the addition of Ca2+. Pinacidil (100 μM) inhibited the potentiation due to GTPγS or noepinephrine but not to phorbol ester. These results suggest that pinacidil has dual effects on vascular smooth muscle contraction. At lower concentrations (>0.1 μM), it decreases [Ca2+]i, possibly by activating ATP-sensitive K+ channels. At higher concentrations (> 3 μM), it may additionally inhibit the receptor-mediated, GTP-binding protein-coupled phosphatidyl inositol turnover.  相似文献   
43.
Advances in processing of surface myoelectric signals: Part 1   总被引:10,自引:0,他引:10  
During sustained voluntary or electrically elicted muscle contractions the surface myoelectric signal is nonstationary and it undergoes progressive changes reflecting the modifications of the motor unit action potentials and their propagation velocity. In particular, during sustained electrical stimulation, the evoked signals show progressive amplitude, time scaling and shape modification. The quantitative evaluation of these changes is important for non-invasive muscle characterisation and may be performed in either the time or frequency domain using parametric and nonparametric spectral analysis as well as alternative methodologies. The paper introduces the detection techniques, reviews and compares the methods of spectral estimation based on FFT and autoregressive models, and discusses their applications and limitations in extracting information from the surface myoelectric signal with particular regard to myoelectric manifestations of localised muscle fatigue during sustained contractions.  相似文献   
44.
断腕再植术后手内在肌挛缩   总被引:11,自引:0,他引:11  
探讨断腕再植术后手内在肌挛缩的发生率、治疗方法及预防。方法:作者总结了近24年内进行断腕再植并得到随访的63例资料,对其中发生手内在肌挛缩41例的发病机理、治疗结果及预防进行了分析和讨论。结果:63例断腕再植术后有41例发生手内在肌挛缩,发生率为65%。缺血时间超过16小时与16小时内的断腕再植术后手内在肌挛缩的发生率,两者差异有显著性意义(t=3.81,p<0.05)。二期行手内在肌手术矫正者效果不理想。结论:断腕再植术后手内在肌挛缩的处理关键在于预防。清创后用肝素化全血对离断手进行灌注,早期行手内在肌筋膜间区减压,将会取得较好的效果。  相似文献   
45.
Effects of Ethanol on the Contractile Function of the Heart: A Review   总被引:7,自引:0,他引:7  
Chronic ethanol consumption leads to a number of alterations in the contractile function of the heart and is a leading cause of cardiomyopathy. Ethanol also has an acute negative inotropic effect mediated by direct interaction with cardiac muscle cells, although this action is often masked by indirect actions resulting from enhanced release of catecholamines in vivo. This article reviews the effects of ethanol on the contractile function of the heart. The specific targets affected by ethanol in cardiac muscle cells are discussed in terms of potential mechanisms underlying the depressions of contractility resulting from both acute and chronic actions of ethanol.  相似文献   
46.
目的:观察改良松解术式治疗耻骨直肠肌综合征的临床效果。方法:2004~2005年采用肛门后横切口耻骨直肠肌全束部分切断术治疗耻骨直肠肌综合征31例。结果:手术总有效率为96·8%。平均住院时间(10·58±2·35)d,平均切口愈合时间(12·16±2·08)d。结论:采用肛门后横切口耻骨直肠肌全束部分切断术的方法疗效确切,具有并发症少、切口愈合时间快和住院时间短的优点。  相似文献   
47.
DOMS (Delayed Onset Muscle Soreness) occurs frequently in sport. DOMS usually develops 12-48 hours after intensive and/or unusual eccentric muscle action. They can be associated with decreased proprioception and range of motion, as well as maximal strength. DOMS disappears 2–10 days before complete functional recovery. Inflammation appears to be the most common explanation. DOMS should not be considered as an indicator of muscle damage but, rather, a sign of the regenerative process, which is well known to contribute to be increase muscle mass. If some treatments are well known to attenuate DOMS, none has been demonstrated to accelerate either structural or functional recovery.  相似文献   
48.
研究正常环指屈肌腱拉伸力学性能和模拟屈肌腱损伤后吻接术后屈肌腱的力学性能,为临床提供生物力学参数。取10个手环指标本,解剖后暴露环指,将标本固定于电子万能试验机底座上,由钢丝绳吊钩沿屈肌腱纵行方向钩住、钢丝绳上端固定于试验机上夹头上,驱动机器,对标本进行拉伸实验,施加拉应力,直至屈肌腱断裂。对断裂后的屈肌腱模拟临床手术进行移位吻接,对10个标本做了腱与腱移位吻接。再对吻接后的标本进行拉伸实验。分别得出了正常组标本和吻接术后标本的拉伸最大载荷、应力、应变等数据。表明:屈肌腱腱与腱吻合组最大载荷、应力、应变均小于正常对照组,但模拟末端编织法吻接术腱与腱吻合组标本,仍具有较好的拉伸力学性能指标。  相似文献   
49.
Summary Muscle cross-section areas were measured by magnetic resonance imaging (MRI) in the thigh of a human cadaver,. the results being compared with those obtained by photography of corresponding anatomic macroslices. A close correlation was found between MRI and photographic evaluation, differences between the methods ranging from nil to 9.5%, depending on the scan position and the muscle groups. In vivo MRI measurements were performed on 12 female and 16 male students, the objectivity, the test-retest reliability and the variability of the MRI measurements being studied by fixing the scan position either manually or by coronary scan. The latter method appeared to be more objective and reliable. The coefficients of variation for muscle cross-section areas measured by MRI were in the range of those for the planimetry of given cross-section areas. Allowing for differentiation between several small muscle bundles in a given area, MRI proved to be a suitable method to quantify muscle cross-sections for intra- and interindividual analysis of muscle size.  相似文献   
50.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号